Bahareh Sara Howard
UNSW Australia
Bahareh Sara is a final year PhD candidate at the Sustainability Assessment Program, School of Civil and Environmental Engineering at the University of New South Wale (UNSW) Australia. Her research aims to contribute to the gap surrounding carbon footprint of whole sector rapid transitions and subsequent implications on various carbon budgets and targets. Through her research, a discrete numerical model has been developed for rapid approximations to the transitioning of the electricity sector through to 100% renewable sources with a main driver being the calculation of carbon emissions where renewable breeding has been found to have a compounding effect.
The ultimate objective of multiple international accords and agreements on climate change has been to curb negative anthropogenic activities to limit or to prevent its most devastating impacts on our planet. To test the effectiveness of mitigation targets for greenhouse gas emissions, various scenarios for the transition of the energy sector to 100% renewable sources have been modeled. Various drivers such as cost of transition, feasibility of resources, economic growth and political and market forces have been considered by several studies. One gap that however remains in most scenario modelling and proposals has been accounting for the full carbon footprint of transition options relative to limiting carbon budgets. These budgets constitute the total amount of greenhouse gas emissions that can still be emitted for a certain level of global warming. According to the latest Paris Agreement the scientific community is encouraged to address this and other knowledge gaps by various means such as modelling scenarios that limit warming to below 1.5 °C relative to pre-industrial levels by set future dates within this century.
In this contribution, we model scenarios for the transition of the electricity sector in Australia, a nation that has ratified the Paris Agreement. We consider the fact that presently, renewable technologies rely heavily on non-renewable sources for coming into existence, contributing to life-cycle GHG emissions in upstream supply chains. At the same time we take into account that the transition needs to be rapid and widely adopted in order to comply with very restrictive carbon budgets. Our modelling approach is distinct in three ways. Firstly, using a discrete numerical computational approach, we model electricity transition scenarios that are realistic, feasible, and commercially viable. Secondly, we account for the compounding effect of the degree of green electrification on future and ongoing technological deployments, evidenced in the beneficial effect of early-stage, mass transition to renewable sources on the cumulative emissions relative to acceptable warming budgets. Thirdly, we compare our scenario results against several others from both governmental agencies and research groups , in terms of cumulative carbon footprint of transition pathways to given dates, taken into consideration the degree of green electrification for all pathways.
Our results show that every scenario under investigation fails to achieve the most ambitious budget of 1.5 °C warming and almost half of them fail the more lenient 2 °C target. Clearly, at this rate, only budgets commensurate with a 2 °C target seem plausible while more ambitious targets appear next to impossible, at best. Additionally, we find that there is a direct correlation between the degree of green transition and the year in which a given budget is breached, suggesting strongly, that a ‘carpe diem’ approach to transition should be taken with vigor. Our results indicate that "early" and "aggressive" deployments of suitable mix from within the pool of available green technologies have a profound effect on cumulative emissions, largely due to the beneficial displacement of ongoing emissions from coal.
